Four-Level SVPWM Strategy of Dual Three-Phase Open-Winding PMSM Drive

To achieve high power rating and low current harmonics of motor drive, this paper develops a dual three-phase open-winding permanent magnet synchronous motor (DTP-OW-PMSM) drive with the DC-link voltage ratio of 2:1:1. Based on this topology, this paper proposes a DTP four-level space vector pulse width modulation (DTP-FL SVPWM) strategy. First, two identical three-phase four-level space vector diagrams are constructed and divided. Then, three adjacent vectors nearest to the reference vector in each diagram are selected for the vector synthesis to guarantee high modulation precision and low switching frequency. Furthermore, to avoid the modulation error caused by the voltage deviation, the proposed DTP-FL SVPWM strategy is further optimized through unified duty ratio compensation (UDRC). The effectiveness of the proposed strategy is verified through experiments.